The usual heparin sodium concentration for anticoagulation during hemodialysis is

• A. 100 u/mL
• B. 5,000 u/mL
• C. 250 u/mL
• D. 1,000 u/mL

Answer: (D)

In hemodialysis, heparin is given in a solution with a defined number of units per milliliter so dosing becomes a simple calculation. The most common strength used is 1,000 units per milliliter. This allows easy conversion of the desired dose in units into milliliters—for example, a 1,000-unit bolus is just 1 mL, and larger doses or infusion rates can be set by measuring how many milliliters of this 1,000 U/mL solution to administer. Using a 1,000 U/mL concentration helps keep dosing straightforward and volume manageable for the patient.

Higher or lower concentrations would require delivering larger or smaller volumes to achieve the same units, which can complicate dosing and increase risks (more fluid added, or potential for overdosing with small-volume mistakes). While some settings might use different preparations, 1,000 U/mL is the standard choice for routine hemodialysis anticoagulation.